Method of and means for reproducing designs



Nav. 2, 1943. o. R. HuGGlNs METHOD OF AND MEANS FOR REPRODUCING DESIGNSFiled May 21, 1941 3 Sheets-Sheet 1 y v INVENTQH I @M LW ,.Q/zm ATTORNEYNov. 2, 1943. o. R. HUGGlNs METHOD OF AND MEANS FOR REPRODUCING DESIGNSFiled May 21, 1941 3 .Sheets-Sheet 2 w R Y O m 5 2]/ 4 W W.v

BY am rc? @W4/[6 ATTORNEY Nov. 2, 1943.

O. R. HUGGINS METHOD 0F AND MEANS FOR REPRODUCING DESIGNS i Filed May21. 1941 5 Sheets-Sheet C5 1 VENTOR` @WM/ @MTTORNEY Patented Nov. 2,1943 METHOD OF AND MEANS FOR REPRODUC- ING DESIGNS Owen R. Huggins,South Norwalk, Conn., assignor to Linotone Corporation, a corporation ofNew York Application May 21, 1941, Serial No. 394,492

Claimsa This invention relates to the art cf making graduatedinstruments, and especially to methods of producing the markings such aslines and iigures which appear thereon.

An example of the usefulness of the present invention is found in themanufacture of range drums used on anti-aircraft guns. Such drums areprovided with a spiral groove having a plurality of lines and guresformed along one edgeV methods by virtue of the fact that each markingis scribed as a separate operation by means of a machine which requiresas another operation a resetting of the machine for each marking.

Aside from the fact that the degree of accuracy required is diiiicult ofattainment by present methods they are open to the objection that themarkings created thereby on one instrument seldom if ever correspondedexactly to the markings on another instrument. Also, since each markingwas created as a separate operation, each marking had to be inspected tomake certain it bore the desired relationship with respect to the othermarkings along the groove. In addition, the markings being scribed, theWalls thereof offered little resistance to the removal of thecontrasting paint with the result that in most cases it soon chipped orafter the instrument had been put in use.

In accordance with the present invention there is provided a method ofproducing the markings on such instruments wherein all the above as wellas other diiiiculties are obviated. To these ends, a die is createdphotomechanically having reproductions of the markings that are to beproduced on theinstruments. These reproductions are preferably createdin relief, and the linear distances between them equals exactly thelinear distances it is desired to have the corresponding markings spacedon the nished instruments. Thereafter, the instrument blanks, afterbeing coated with a suitable resist, are applied one after anotheragainst the relief reproductions on the die to cause these reproductionsto cut through or otherwise displace the resist coating and so bare theunderlying areas on the blanks. Then the blanks are subjected to theaction of an etchant to etch out the areas on the blanks thus bared andso produce the desired markings in intaglio on theblanks; and finallythe blanks are washed to remove the remaining areas of the resistcoating.

Inasmuch as the markings are produced on the blanks by means of a die,the only requirement necessary to insure that the markings on oneinstrument correspond with the markings on another is that the blanks beduplicates of one another, and this, of course, is a simple requirementin View of the present day nishing machines. Also, since the markingsare produced on the blanks by means of a die, it is only necessary toinspect one or at the most a few of the markings instead of them all toinsure that they occupy their intended positions on the instruments. Inadditionthe markings, being etched out, offer greater resistance to theremoval therefrom of the contrasting paint.

For a more complete description of the invention reference may be madeto the accompanying drawings wherein:

Figure 1 is a perspective View of a range drum having markings such aslines and numbers located along a spiral groove;

Figure 2 is a plan view of a flat copy showing black on whitereproductions of the markings to be formed along the groove;

Figure 3 is an enlarged plan vi'eW of a portion of the negative of thecopy; v

Figure 4 is a schematic view showing the arrangementI employed indefining the areas to be etched on the die;

Figure 5 is a plan View of a iiat die;

Figure 6 is a schematic view showing the manner in which the areas to beetched on the drums are defined with the aid of the die;

Figure 7 is a schematic view of a modified arrangement employed in thecreation of a roller die;

Figure 8 is a perspective view of a' roller die;

Figure 9 is a schematic view of the arrangement employed to define theareas to be etched on the drum with the aid of the roller die; and

Figure 10 is a side elevation of apparatus employed in creating anegative.

In describing the invention, a range drum has been chosen for purposesof illustration. Such drums ,are made from blanks 20 cut from tubularstock and are provided with a spiral groove 2| having markings 22 formedalong one edge thereof. v

In accordance with the preferred embodiment of the invention, themarkings 22 are formed on the blanks'2ll before the groove 2| is cut,the reason for this being explained later. In forming the markings 22 onthe blank 20, a fiat die 23 is created photomechanically havingreproductions 24 of the markings 22 preferably in relief and in such amanner that the linear distances between the reproductions are lexactlythe same as it is desired to have the corresponding markings spacedalong the groove 2| on the finished drums (see Fig. To this end, a iiatphotographic copy 25 is made by hand having non -liglit reiiectingreproductions 26 of the markings 22 on alight reiiecting background 2l(see Fig. 2). The copy' 25, in effect, comprises a development of themarkings 22 as they are to appear on the instruments, and it ispreferably made oversize since this leads to greater accuracy inpreparing the copy.

After the` copy 25 has been prepared, it is mounted on the copy board 28of a camera 29, and a light sensitive lm or plate 30 in the camera 29 isexposed thereto. The film or plate 3B is then removed from the camera 29and developed.l The resultant negative 30 will be substantially opaquesave for transparent areas 3| which correspond to the non-lightreflecting reproductions 26 of the markings on the copy 25 (see Fig. 3).Prior to the exposure of the film or plate, however, the camera 29 iscarefully focused to make certain that the linear distances between thetransparent areas or reproductions 3| on the negative 30 are exactly thesame as the linear distances it is desired that the correspondingmarkings be spaced along the groove 2| on the finished instruments.

The negative 30 thus prepared is then placed in intimate contact with alight sensitive coating applied on the surface of a flat metal plate 23and light from any suitable source, such as a lamp 32, is directedthrough the transparent areas 3| on to the underlying areas of the lightsensitive coating on the plate 23. The negative 30 is then removed, andthe coating on the plate 23 developed to render resistant those areas 24affected by light and which constitute reproductions of the markings itis desired toproduce on the finished instruments. The 'plate 23 is thenwashed to remove the unexposed portions of the coating and thus bare theunderlying areas of the plate 23; and finally, the plate 23 is,subjected to the action of acid to etch away those areas thus bared.During this etching operation, those areas 24 protected by the resistand which, as stated heretofore, constitute reproductions of themarkings to be formed along the groove 2| on the finished drums remainsubstantially unaffected. Thus the plate 23 is converted into a diehaving reproductions 24 in relief of the markings to be produced, andthe linear distances between these markings are exactly the same as thelinear distances it is desired to have the corresponding markings spacedalong the groove 2| on the finished instruments.

The die 23 thus made is then clamped to a table (not shown) capable ofbeing reciprocated back and forth in a fixed path, and a blank 20 to beetched, after being machine finished to substantially the exact diameterrequired and coated with a suitable resist, is rotatably mounted abovethe die 23. Then the blank 2U is brought into engagement with the die 23and the die 23 moved therebeneath (see Fig. 6) from one end of thereproduction thereon to the other during which time the blank 20 makesone complete turn.

As the die 23 travels beneath the blank 20, the relief reproductions 24cut through or otherwise displace the resist and so bare the underlyingareas on the blank 2l), thus creating reproductions of the markings 22on the blank 20 in the form of etchable areas and in the exact locationit is desired the markings occupy along the groove 2|. Thereafter, theblank 20 is subjected to the action of acid to etch out thereproductions thus created and so form, as engravings, the desiredmarkings 22 on the blank 20.

As stated heretofore, the groove 2| isformed after the markings 22 havebeen formed on the blank, this being desirable since otherwisedifficulty might be experienced in obtaining a coating of even thicknesson the blanks. Also, the groove 2| is preferably formed mechanically,and since the machines for so forming a groove of this type are Wellknown in the art no description thereof is deemed necessary. After thegroove 2| and markings 22 are formed they are usually renderedcontrasting in appearance as by painting the markings 22 white and theremainder of the engraved surface black.

As previously stated, since the markings 22 are produced on the blanks20 by means of a die, the only requirement necessary to insure that themarkings 22 on one instrument are substantial duplicates of the markings22 on another instrument is that the blanks 20 be machine finished tosubstantially the same diameter.

Also, since the markings 22 are produced on the blanks 20 by means of adie, itis only necessary to inspect one or at the most afew of the mark-'ings 22 to insure they all occupy their intended position along thegroove 2|. As a matter of fact, the die 23 may be provided with means(not shown) for forming inspection marks on the blanks 20 at the sametime the reproductions of the markings 22 are formed thereon. Under suchconditions, the inspection marks could be checked or inspected foraccuracy and then painted out or otherwise protected against the actionof acid before the etching operation so that they would not appear onthe finished instrument. In addition, the markings 22 thus created onthe instruments, being etched, have slightly pitted side and bottomWalls which serve to hold the contrasting paint. Also, during theetching out of the markings 22, the edge of the resist coating whichdefines the areas to be etched becomes slightly undercut and so foldsdownwardly and protects the upper edges of the side walls of themarkings against the action of acid with the result that a shoulder (notshown) which serves to retain the paint is formed about lthe upper edgesof the markings 22.

In accordance with another embodiment of the invention, a roller die isused in place of the flat die 23 described above. In marking the rollerdie, the black on white copy 25 is photograped onto a flexible lrn 4|which is then developed to create a negative all in the manner describedheretofore. The flexible negative 4| is then trained over a roller blank42 coated with a light sensitive substance, and one-half the image area4|a as measured from one end thereof is brought into intimate contactwith the light sensitive coating. Thereafter, light from any suitablesource such as that created by lamps ,43, is directed through thetransparent areas of that-one-half portion of the negative in contact'with the light sensitive coating on the roller onto' those portions ofthe coating underlying the same. 'Ihen theremaining half of the imagearea 4Ib of the negative 4l is brought into intimate contact with theother half of the sensitized surface of the roller and light isprojected through the transparent areas thereof onto the underlyingareas of the sensitized coating. Prior to this second exposure, caremust be exercised to make certain that the end of the reproductioncreated on the sensitized surface of the blank 42 during the firstexposure joins with the end of the second half of the image area' or thenegative 4I, otherwise the ,reproductions of the markings created duringthe second exposure will not bear the intended relationship with thereproductions of the markings created during the first exposure. Afterthe second exposure, the light sensitive coating on the blank 42 isdeveloped to render the light affected areas resistant to the action ofacid Then the blank 42 is washed to remove the remaining unexposed areasof the sensitizedcoating; and finally it is subjected to the action ofacid to etch away those portions bared by the removal of the lightunaffected areas of the coating. Thus the blank 42 is converted into a froller die having reproductions in relief of the markings to be producedon the instruments.

The roller die 42 thus created may then be rotatably mounted, and theinstrument blanks 2li after being coated with an acid resist broughtinto rolling engagement therewith one after-another (see Fig. 9). Duringthis rolling engagement, the relief reproductions 44 on the die 42 cutthrough or otherwise displace the coating and so bare the underlyingareas on the blanks 20. Thereafter, the blanks 20 are subjected to theaction of acid to etch out the areas thus bared and so form the markings22 in the form of engravings.

In either embodiment the coating of resist may, if desired, be omittedfrom the blanks 20 before they are applied to the die. Under theseconditions, the pressure between the two would have to be such as toscore the surface of the blanks 2D. Thereafter, a coating of resistCould be rolled over the blanks 20 to protect against the action of acidall areas save the scored areas, and finally the blanks 2D etched toform the markings 22 thereon.

Also, in either embodiment, the' relief reproductions of the markings onthe die could be inked with a suitable resist and the blanks rolled overthe die, during which operation the resist would be deposited on thesurface of the blanks. Then when the blanks are etched, the markings 22will appear in relief along the groove 2|.

In addition, in either embodiment, the reproductions on the die could beinked with an opaque ink and the blanks after being coated with a lightsensitive emulsion rolled against the die, during which operation theink would be deposited on the sensitized surface of the blanks. Then thecoating could be developed, the inked areas and the underlying areas ofthe coating removed and the blanks etched to form the markings 22thereon.

The invention also contemplates the use of an intaglio die, and in suchcase, positives are made from the negatives and these positives used inplace of negatives in the above-described arrangements for making thedie. When an intaglio die is used, the recessed areas could beThereafter, the blanks could be etched and the markings would be formedin relief.l Alternatively, the recessed areas on the intaglio die couldbe filled with an opaque ink and the blanks after being coated with alight sensitive emulsion brought into engagement therewith 'erectionbetween the die end the Menke than that provided by the reliefreproductions on the die, whether it be either the ilat die or theroller die in order to prevent slippage, such additional traction may beprovided by forming on each side of the copy a narrow row of spacedangularly disposed non-light reecting lines .41. Such lines, of course,will show up as transparent lines on the negative and as lines 48 inrelief on the die 23 where they will serve as racks. In such cases, thelines on the copy will be spaced so that the vdistance between the racksformed thereby on. the die is greater than the length Y of the nisheddrum. When such traction is provided, the drum blanks 20 are madeoversize in length so that the ends thereof will be engaged by the rackson the die, and then cut to the desired length either before or afterthe etching out of the markings on the drums.

In addition, the invention contemplates the use of a lm in the making ofa die wherein the reproductions of the markings arecreated mechanicallyas by scriblng them through the emulsion instead of photographing themfrom a copy.

Having thus described my invention, what I claim is:

1. In the method of producing a range drum having a spiral groove withmarkings along one edge thereof, the steps which include providing ablank machine finished to substantially the exact diameter required,photoengraving the markings on said blank, and then mechanically formingthe groove on the blank.

2. In the method of producing the requisite markings on a range drum orthe like, the steps which include creating a flat die having in reliefreproductions of said markings, providing said die with a frictioncreating rack 'along a portion of its length, preparing a drum blankmachine finished to substantially the exact diameter required, coatingsaid blank with an acid resist, mounting said blank above said die,bringing said blank into engagement with said die adjacent one endthereof, moving said die beneath said coated blank to cause the reliefreproductions thereon to displace like areas of the coating on theblank, removing said blank from above said die and then subjecting theblank to the actionof acid to etch the areas thereof underlying thedisplaced areas of the coating.

3. In the method of producingV the requisite markings on a range drum orthe like, the steps which include creating a die having reproductions inrelief of said markings, preparing a drum blank machine finished tosubstantially the exact diameter required, coating said -blank with anAacid resist, bringing said blank into engagement with said die, causingrelative movement between said blank and said die under the inuence ofmeans which prevents slippage therebetween to cause the reliefreproductions on the die to displace like areas of the coating on theblank, and thereafter subjecting the blank to the action of acid to etchthe areas thereof underlying the displaced areas of the coating.

4. In the method of producing the requisite markings 0n a range drum orthe like, the steps which include creating a die having reproductions inrelief of said markings, preparing a drum blank machine finished tosubstantially the exact diameter required, coating said blank with aresist, bringing said blank intc engagement with said die, causingrelative movement between said blank and said die to cause the reliefreproductions on the die to displace like areas of thel coating on theblank, and thereafter subjecting the blank to the action of an etchantto etch the areas thereof underlying the displaced areas of the coating.

5. In the method of producing the requisite markings on a range drum orthe like, the steps which include creating a die having reproductions inrelief of said markings, preparing a drum blank machine finished tosubstantially the exact diameter required, coating said blank with aresist, bringing said blank into engagement with said die, causingrelative movement between said blank and said die to cause the reliefreproductions on the die to displace like areas of the coating on theblank, subjecting the blank to .the action of an etchant to etch theareas thereof underlying the displaced areas of' the coating, and thenmechanically forming the groove l OWEN R. HUGGINS.

l5 on the blank.

